Chapter 7

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Transcript of Chapter 7

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Learning

Chapter 7

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Learning

What is Learning (association)?

Classical Conditioning and Behaviorism Pavlov’s Experiments (description and

application) US, CS, CR, UR; Acquisition, extinction… Recovery and Stimulus discrimination and

generaliztion

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Operant Conditioning Skinner’s Experiments

Shaping, Reinforcement and Punishment Reinforcement schedules

Extending Skinner’s Understanding Skinner’s Legacy Contrasting Classical & Operant

Conditioning

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Learning by Observation Bandura’s Experiments Applications of Observational

Learning

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Definition

Learning is a relatively permanent change in an organism’s behavior due to

experience.

Our learning is more flexible in comparison to the genetically-programmed

behaviors of salmon, for example.

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How Do We Learn?

We learn by association. Our minds naturally connect events that occur

in sequence. 2000 years ago, Aristotle suggested

this law of association. Then 200 years ago Locke and Hume

reiterated this law.

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Associative Learning

Learning to associate one stimuluswith another.

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Ideas of classical conditioning originate from old philosophical theories.

However, it was the Russian physiologist Ivan Pavlov who elucidated classical

conditioning.

His work provided a basis for later behaviorists like John Watson.

Classical Conditioning

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Pavlov’s Experiments

Before conditioning, food (Unconditioned Stimulus, US) produces salivation (Unconditioned Response, UR).

However, the tone (neutral stimulus) does not.

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Pavlov’s ExperimentsDuring conditioning, the neutral stimulus (tone) and the US (food) are paired, resulting in salivation (UR).

After conditioning, the neutral stimulus (now Conditioned Stimulus, CS) elicits salivation (now Conditioned Response, CR).

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Classical Conditioning Acquisition defined.

1. Timing of the neutral stimulus.

2. The time in between the two stimuli should be about half a second.

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Extinction

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Spontaneous Recovery

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Stimulus Generalization

Generalization defined -

Pavlov conditioned the dog’s salivation (CR) by pairing touch on the thigh (CS) with food

(US).

When he subsequently stimulated other parts of the dog’s body, the dog salivated as well but not as strongly as it salivated when

touched on the thigh.

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Stimulus Discrimination

Discrimination defined

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Extending Pavlov’s Understanding

Pavlov and Watson (the Behaviorists) considered consciousness, or mind, unfit for the scientific study of psychology.

However, they underestimated the importance of cognitive processes and biological constraints.

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Cognitive Processes

Early behaviorists believed that learned behaviors of various animals could be

reduced to mindless mechanisms.

However, later behaviorists suggested that animals learn the predictability of a stimulus, meaning they learn expectancy or awareness of a stimulus (Rescorla &

Wagner, 1972).

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Biological Predispositions

John Garcia

Garcia showed that the duration between the CS and the US may be long (hours), and still result

in conditioning.

Courtesy of John G

arcia

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Biological Predispositions

Even humans can develop classically to conditioned nausea.

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Pavlov’s greatest contribution to

psychology is isolating elementary behaviors

from more complex ones through objective

scientific procedures.

Pavlov’s Legacy

Ivan Pavlov(1849-1936)

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1. Former crack cocaine users should avoid cues (people, places) associated with previous drug use.

2. Through classical conditioning, a drug (plus its taste) that affects the immune response may cause the taste of the drug to invoke the immune response.

Applications of Classical Conditioning

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Watson used classical conditioning procedures to develop advertising

campaigns for a number of organizations,

including Maxwell House, making the “coffee break” an American custom.

Applications of Classical Conditioning

John B. Watson

Brow

n Brothers

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Operant & Classical Conditioning

1. Classical conditioning forms associations between stimuli (CS and US). Operant conditioning, on the other hand, forms an association between behaviors and the resulting events.

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Operant & Classical Conditioning

2. Classical conditioning involves respondent behavior that occurs as an automatic response to a certain stimulus. Operant conditioning involves operant behavior, a behavior that operates on the environment, producing rewarding or punishing stimuli.

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Skinner’s Experiments

Skinner’s experiments extend Thorndike’s thinking, especially his law of effect. This law states that rewarded

behavior is likely to occur again.

Yale U

niversity Library

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Shaping

Shaping is the operant conditioning procedure in which reinforcers guide behavior towards the desired target

behavior through successive approximations.

A rat shaped to sniff mines. A manatee shaped to discriminateobjects of different shapes, colors and sizes.

Kham

is Ram

adhan/ Panapress/ Getty Im

ages

Fred Bavendam

/ Peter Arnold, Inc.

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Types of Reinforcers

Reinforcement: Any event that strengthens the behavior it follows. A

heat lamp positively reinforces a meerkat’s behavior in the cold.

Reuters/ C

orbis

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1. Primary Reinforcer: An innately reinforcing stimulus like food or drink.

2. Conditioned Reinforcer: A learned reinforcer that gets its reinforcing power through association with the primary reinforcer.

Primary & Secondary Reinforcers

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1. Immediate Reinforcer: A reinforcer that occurs instantly after a behavior. A rat gets a food pellet for a bar press.

2. Delayed Reinforcer: A reinforcer that is delayed in time for a certain behavior. A paycheck that comes at the end of a week.

Immediate & Delayed Reinforcers

We may be inclined to engage in small immediate reinforcers (watching TV) rather than large

delayed reinforcers (getting an A in a course) which require consistent study.

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Reinforcement Schedules

1. Continuous Reinforcement: Reinforces the desired response each time it occurs.

2. Partial Reinforcement: Reinforces a response only part of the time. Though this results in slower acquisition in the beginning, it shows greater resistance to extinction later on.

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Interval Schedules

1. Fixed-interval schedule: Reinforces a response only after a specified time has elapsed. (e.g., preparing for an exam only when the exam draws close.)

2. Variable-interval schedule: Reinforces a response at unpredictable time intervals, which produces slow, steady responses. (e.g., pop quiz.)

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Schedules of Reinforcement

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Punishment

An aversive event that decreases the behavior it follows.

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Punishment

1. Results in unwanted fears.2. Conveys no information to the organism.3. Justifies pain to others.4. Causes unwanted behaviors to reappear

in its absence.5. Causes aggression towards the agent.6. Causes one unwanted behavior to appear

in place of another.

Although there may be some justification for occasional punishment (Larzelaere &

Baumrind, 2002), it usually leads to negative effects.

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Cognition & Operant Conditioning

Evidence of cognitive processes during operant learning comes from rats during

a maze exploration in which they navigate the maze without an obvious

reward. Rats seem to develop cognitive maps, or mental representations, of the

layout of the maze (environment).

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Intrinsic Motivation

Intrinsic Motivation: The desire to perform a behavior for its own sake.

Extrinsic Motivation: The desire to perform a behavior due to promised rewards or threats of punishments.

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Skinner’s Legacy

Skinner argued that behaviors were shaped by external influences instead of

inner thoughts and feelings. Critics argued that Skinner dehumanized people by

neglecting their free will.

Falk/ Photo Researchers, Inc.

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Applications of Operant Conditioning

At Home

In children, reinforcing good behavior increases the occurrence of these

behaviors. Ignoring unwanted behavior decreases their occurrence.

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Operant vs. Classical Conditioning

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Learning by Observation

Higher animals, especially humans,

learn through observing and

imitating others.

The monkey on the right imitates the

monkey on the left in touching the pictures in a certain order to

obtain a reward.

© H

erb Terrace

©H

erb Terrace

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Mirror Neurons

Neuroscientists discovered mirror neurons in the brains of animals and

humans that are active during observational learning.

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Imitation Onset

Learning by observation begins

early in life. This 14-month-old child

imitates the adult on TV in pulling a toy

apart.

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Bandura's Experiments

Bandura's Bobo doll study (1961) indicated that individuals (children) learn through

imitating others who receive rewards and punishments.

Unfortunately, Bandura’s studies show that antisocial models (family, neighborhood or

TV) may have antisocial effects.

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Television and Observational Learning

Gentile et al., (2004) show that children in elementary school who are exposed to

violent television, videos, and video games express increased aggression.

Research shows that viewing media violence leads to an increased expression

of aggression.

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Positive Observational Learning

Fortunately, prosocial (positive, helpful) models may have prosocial effects.

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